A conventional mediation server receives image data from a mobile device and controls a multifunction peripheral (MFP) to print an image based on this image data. Specifically, the mediation server transmits to the MFP a QR code (registered trademark) that includes a job ID to the MFP in response to a request from the MFP. The MFP displays this QR code. Using a reading unit of the mobile device, the user of the device scans the QR code displayed on the MFP to acquire the job ID. After acquiring the job ID, the mobile device transmits an upload request to the mediation server that includes image data and the job ID. After the image data has been uploaded to the mediation server, the MFP transmits an image data acquisition request including the job ID to the mediation server and subsequently receives the image data from the mediation server and prints the image based on the image data.